Abstract: A magnetic resonance scanner has a base, a C-arm mounted on the base, the C-arm having an inner surface curved in a C-shape, the C-shape defining a plane, a magnet mounted on the inner curved surface of the C-arm, the magnet generating a basic magnetic field for magnetic resonance imaging, and a drive mechanism mechanically connected to the magnet. The drive mechanism rotates the magnet around an axis that is orthogonal to the plane so as to selectively position the magnet in at least two magnet positions that are respectively above and beneath a patient, who is situated in the C-arm along or parallel to the axis.

Abstract: In a method and apparatus for capturing magnetic resonance data from an imaging volume of a patient in which liquid, such as particular blood, is moving, a bSSFP magnetic resonance sequence is executed in which nuclear spins located within the imaging volume are cyclically excited by radiation of a radio-frequency pulse, using a magnetic resonance scanner. A ramp pulse is used as the radio-frequency pulse, which establishes a flip angle of the spins that is spatially variable within the imaging volume. The flip angle is designed to be lower on a side or the imaging volume from which the liquid flows into the imaging volume than on the side at which the liquid flows out, and the flip angle increases monotonically.

Abstract: A method for reconstructing dynamic image data is described. In the method, raw data is acquired in a time-dependent manner from an examination region, wherein at least some of the raw data is assigned various values of movement parameters. First time-dependent image data based on acquired raw data is reconstructed. Furthermore, deformation fields based on the first image data are determined as a function of at least two time-dependent movement parameters. Based on the deformation fields, the raw data and the first image data, corrected image data is then generated. Furthermore, a reconstruction apparatus is described. Moreover, a magnetic resonance imaging system is described.

Abstract: A magnetic resonance scanner has a base, a C-arm mounted on said base, the C-arm having an inner surface curved in a C-shape, the C-shape defining a plane, a magnet mounted on said inner curved surface of said C-arm, the magnet generating a basic magnetic field for magnetic resonance imaging, and a drive mechanism mechanically connected to the magnet. The drive mechanism rotates the magnet around an axis that is orthogonal to said plane so as to selectively position said magnet in at least two magnet positions that are respectively above and beneath a patient, who is situated in the C-arm along or parallel to the axis.

Abstract: A magnet assembly for magnetic resonance imaging is used to generate the basic magnetic field with a strength needed to produce the steady state or equilibrium position of nuclei or nuclear spins in magnetic resonance imaging. This magnet, or a part thereof, is vibrated or tilted or otherwise periodically moved so as to change its position and thereby generate a time-varying gradient field, which is used to enter the acquired magnetic resonance signals as raw data into k-space.

Abstract: Techniques are described for controlling a magnetic resonance imaging system to facilitate an improvement in Simultaneous Multislice Imaging, especially concerning a compensation of eddy currents. This is achieved by simultaneously measuring at least two slices by the magnetic resonance imaging system while applying a pulse sequence. In the course of the pulse sequence for measuring k-space lines, a set of in-plane encoding signals (that are typically gradients) are applied with a set of Hadamard encoding signals in an interleaved scheme.

Abstract: In a method for controlling a magnetic resonance imaging system as part of functional magnetic resonance imaging, a main magnetic field B0 is provided having a field strength of at most 1.4 tesla at a main field magnet system (4) of the magnetic resonance imaging system (1); and a measurement is performed as part of functional magnetic resonance imaging, wherein a measurement sequence (MS) is applied that has a longer echo time TE (e.g. longer than 100 ms).

Abstract: In a magnetic resonance method and apparatus for time-of-flight vascular imaging, a magnetic field is applied to an imaging volume and an inflow volume, from which liquid enters into the imaging volume, of an examination person. The imaging volume is excited by an RF pulse, which fulfills a magnetization transfer function and a fat saturation function, while the magnetic field is being applied. The RF pulse has a frequency distribution whose frequencies are higher than the center frequency of water in the imaging volume, and that includes the fat frequency in the imaging volume. The magnetic field has a field distribution with an apex with essentially no spatial gradient in the imaging volume and having a higher spatial gradient in the inflow volume, so that the center frequency of water in the inflow volume is shifted in the direction of lower frequencies and is no longer affected by the RF pulse.

Abstract: The disclosure relates to a medical image acquisition device with a pilot tone transmitter and a pilot tone receiver and to a method for operating the same. The pilot tone transmitter is configured to emit an electromagnetic radio frequency signal into a patient. The pilot tone receiver is configured to receive the radio frequency signal and to decode an item of information relating to a physiological process in the patient. The pilot tone transmitter has a modulator configured to modulate the electromagnetic radio frequency signal with a code and the pilot tone receiver is configured to select the modulated radio frequency signal using the encoding from a plurality of signals.

Abstract: In a parameter value determination method, parameter values are determined based on at least two previously determined most similar comparison signal curves. As a result, the parameters for determining can be determined with a resolution greater than the resolution, underlying the comparison signal curves, of the values of the parameters to be determined. Advantageously, the determination of the parameter values are not limited to the values of the comparison signal curves, in other words, are not limited to the lattice/grid of the dictionary.

Abstract: A magnetic resonance fingerprinting (MRF) method for determining parameter values in pixels of an examination object can use a magnetic resonance system with, for example, a constant magnetic field strength (e.g. of less than 1.5 tesla or a constant magnetic field strength of less than 0.5 tesla). The MRF method can be adapted for conditions that prevail with such low-field magnetic resonance systems, thus enabling the parameter values to be advantageously determined efficiently while simultaneously maintaining a high degree of quality.

Abstract: A method is provided for ascertaining at least one item of movement information describing a sought movement as a partial movement of an overall movement in an at least partially moved examination region. In the method, at least one excitation signal having a first frequency band is output and receiving signals generated by the excitation signal are recorded with a receiving coil arrangement, (e.g., a receiving coil arrangement of a magnetic resonance device), having a plurality of receiving channels. The coils of the receiving coil arrangement are designed to record a receiving frequency band including the first frequency band, wherein for ascertaining the movement information the complex receiving signals of the receiving channels are combined at one instant according to a combination specification ascertained over a period by an analysis of the receiving signals that identifies at least one component of a movement that contributes to the sought movement.

Abstract: For machine training and application of a trained complex-valued machine learning model, an activation function of the machine learning model, such as a neural network, includes a learnable parameter that is complex or defined in a complex domain with two dimensions, such as real and imaginary or magnitude and phase dimensions. The complex learnable parameter is trained for any of various applications, such as MR fingerprinting, other medical imaging, or non-medical uses.

Abstract: Machine training a network for and use of the machine-trained network are provided for tissue parameter estimation for a magnetic scanner using magnetic resonance fingerprinting. The machine-trained network is trained to both reconstruct a fingerprint image or fingerprint and to estimate values for multiple tissue parameters in magnetic resonance fingerprinting. The reconstruction of the fingerprint image or fingerprint may reduce noise, such as aliasing, allowing for more accurate estimation of the values of the multiple tissue parameters from the under sampled magnetic resonance fingerprinting information.

Abstract: A magnetic resonance tomography scanner is provided for the determination a diffusion tensor of an examination object, and a method is provided for operating the magnetic resonance tomography scanner. The magnetic resonance tomography scanner acquires a volume image of the examination object by imaging magnetic resonance tomography without diffusion encoding. The control system segments the image according to diffusion-relevant symmetry properties and also determines volume elements of a symmetry group. A first and a second component of a diffusion tensor are acquired by the magnetic resonance tomography scanner at different angles and the control unit uses the symmetry property with the acquired components and the volume image to determine a diffusion tensor for the volume elements.

Abstract: In a method and apparatus for determining parameter values in voxels of an examination object using magnetic resonance fingerprinting (MRF), a first signal comparison is made of signal characteristics of established voxel time series with first comparison signal characteristics. Further synthetic comparison signal characteristics are generated from the first comparison signal characteristics and values determined in the first signal comparison. The generated further comparison signal characteristics are used to perform a further signal comparison, with which values of at least a first and a second further parameter are determined. From the further comparison signal characteristics, a value of at least one further parameter is determined that could not necessarily already be determined in the first signal comparison.

Abstract: A method for post processing and displaying a three-dimensional angiography image data set of a blood vessel tree of a patient, wherein two-dimensional display images are rendered from the angiography image data set and displayed, wherein two display images are rendered from the angiography image data set using viewing directions forming an angle suited for stereoscopic perception of the display images and both display images are simultaneously displayed on a display screen in a display presentation that causes each display image to be viewed by one eye of a person viewing the display screen.

Abstract: A method for generating a movement signal of an object such as a body part of a human or animal is provided. The movement signal provides quantitative information on a movement of the object. The method includes acquiring an electromagnetic navigation signal such as a Pilot Tone signal from the object. The electromagnetic navigation signal is modulated by movements of the object. A reference signal is extracted from the navigation signal, and a parameter having a known time-dependency is determined from the reference signal. The navigation signal is corrected based on the parameter or a time-average of the parameter to reduce a signal drift in the navigation signal. The movement signal is extracted from the corrected navigation signal.

Abstract: Techniques are disclosed for providing a first magnetic resonance fingerprinting dictionary using fingerprints having a first length. A transformation matrix is also utilized that is configured to shorten the fingerprints to a second length that is shorter than the first length. A second magnetic resonance fingerprinting dictionary may then be obtained by multiplying the first magnetic resonance fingerprinting dictionary with the transformation matrix, with the fingerprints of the magnetic resonance fingerprinting dictionary having the second length. This facilitates the storage of a MRF dictionary that takes up less storage space and decreases the time taken to perform scanning operations.

Abstract: In a magnetic resonance method and apparatus, each repetition of a multi-repetition scan, (a) an RF excitation pulse is applied to the subject under examination, (b) a slice-selection gradient is activated while the RF excitation pulse is being applied, (c) further gradients for spatial encoding are activated, and (d) measurement data are acquired as an echo signal produced after the RF excitation pulse. Steps (a) to (d) are repeated until a desired number of RF excitation pulses have been applied. An additional dedicated dephasing gradient is switched in each case such that a transverse magnetization of the spins to be excited by an RF excitation pulse is sufficiently dephased before each applied RF excitation pulse.